Means for reducing the froth formation at centrifugal liquid separators and the like



June 18, 1929. 5, w, RUDA 1,718,081

MEANS FOR REDUCING THE FROTH FORMATION AT CENTRIF'UGAL LIQUID SEPARATORS AND THE LIKE 2 Sheets-Sheet 1 Filed Sept. 24, 1927 June 18, 1929. a. w. RUDA 1,718,081

mmus FOR manucme THE FROTH FORMATION AT cnu'rnrrueu.

LIQUID SEPARATORS AND was 1.1m:

Filed Sept. 24, 1927 2 Sheets-Sheet 2 J l 6 dc g 7 hw/e/wag W WM Patented June 18, 192 9.

7 UNITED STATES 1, I 1,718,081 ATEVNT OFFICE,

GUSTAF WILI-IEIlM RU'DA, OF SODERTELJE, SWEDEN, ASSIGNOR TO AKTIEBOLAGET BALTIC, F STOCKHOLM, SWEDEN.

MEANS FOR REDUCING THE FROTII FORMATION AT CENTRIFUGAL LIQUID SEPA- RATORS AND THE LIKE.

Application f led September 24, 1927, Serial No. 221,836, and in Sweden August 25, 1927.

In the separating of milk or other liquids it is desired that the liquid may leave the separator at theslightest possible velocity, because the formation of froth is thereby reduced. For that purpose discharge passages for the liquid have been provided in the wall of the separator bowl or in a member connected to the same, which passages extend rearwardly relatively to the rotary direction of the bowl in an oblique direction or along a curve. Hitherto, the best result has been gained by the liquid being discharged through channels extending rearwardly along a cur've. The effecting of such channels, however, is diflicult and besides the arrangement involves some drawbacks. In order that the reducing of the froth formation in a separator thus arranged may be so effective as possible, the liquid ought to be discharged througha few .number of channels and in solid streams. The length of the discharge weir then constitutes a slight portion of the circumference of the separator bowl, for which reason in separators thus arranged variations of the proportion of the discharged liquids (for in stance cream and skimmilk) easily occur, as the velocity of the bowl or the supply of liquid varies. I

This invention relates to means for reducing the froth formation which is superior to means for the same purpose hitherto known, owing to the fact that it not only possesses better qualities for reducing the froth formation but besides is more simple regarding its construction and may be manufactured at reduced expenses.

The invention is characterized chiefly by a groove or the like substantially concentric with the weir and so located with relation to the same, that the liquid passing the weir enters the groove, the said groove being stopped up at its front end with relation to the rotary direction of the bowl, so that the liquid, which has entered the groove is coinpelled to move in the opposite direction and to a discharge opening, through which it thus passes at reduced velocity. Hereby, the froth formation is reduced in an especially effective manner and at the same time the power consumption is considerably reduced. The weir determining the position of the liquid level in separators thus arranged has a great length, for which reason variations in the velocity of theseparator and the supply of liquid have a very slight influence upon the proportions of the discharged llquids, which is of great importance. Qwing to the fact that the collecting groove is open inwards along its whole length, it may easily be cleaned. i

Some forms of execution of the invention are illustrated as examples in the accompanying drawings. Fig. 1 shows in a vertical section the bowl of a cream separator for motor power to which the invention has been applied. Fig. 2 shows in a vertical section the top part of a separator bowl in which the discharge means for the skimmilk and the cream are arranged in accordance with the invention. Fig. 3 shows in a horizontal section 011 the line IIII in Fig. 1 and on a greater scale the discharge means. Fig. 4; is a horizontal section of the discharge means according to a modifiedform of the invention. Fig. 5 shows viewed from the inner side a portion of the collecting groove located at the discharge opening.

1, Figs. 1 and 3,. is the bowl of the separator, comprisingthe bowl body and the cover, ,2 is a weir for the separated liquid (the skimmilk) provided in the top part of the bowl, 3 a liquid collecting groove provided in the wall of the bowl above the weir and concentric to the same, and 4 a radially extending opening provided in the wall of the bowl and adapted to discharge the liquid contained in the groove 3. The said groove 3 is closed at its front end 5 relatively to themtary direction of the bowl, consequently toward. the opening 4. A shield 6 prevents liquid from passing from the bowl directly to the discharge opening 4, without having previously passed through the groove 3. The groove 3 is throttled at the part 7 located at the discharge opening, Fig. 5. 8 is the centertube, 9 the ordinary discs, and 10 the cream-screw. I

The device. operates in the following manner. The milk is supplied through the centertube 8 and distributed in the spaces between the discs 9 in the ordinary manner. The skimmilk leaving the separator passes over the weir 2 into the groove 3. Inthe groove 8, which ought to have such dimensions that the liquid does not fill up the same completely, a pressure is created through the action of the centrifugal force, which owing to the bar 5 compels the liquid to move in the direction indicated by the arrow a, Fig. 3, opposite to the rotary direction of the bowl, indicated by the arrow Z), and at a comparatively great velocit which results in the liquid leaving the separator at a considerably reduced velocity. The efl'ect is still more increased by the groove 3 being throttled at 7 close to the discharge opening 4, Fig. 5. The cream is discharged through the screw 10.

The separator bowl may, evidently, be provided with more than one groove with discharge opening. Thus, Fig. 4 shows a separator bowl provided with two grooves 3 and 3* with corresponding discharge openings 4 and 4*.

In the separator bowl shown in Fig. 2 discharge means 2, 3, 4 arranged as described above for reducing the froth formation is provided for the skinimilk and similar discharge means 2 3, 4 for the cream, the latter thus substituting the cream-screw 10.

I claim:

1. In means for reducing the formation of froth in centrifugal liquid separators and the like the combination of the bowl, a weir for the separated liquid provided in the neck of the bowl and comprising the whole part of the periphery of the said neck not open outwards for the discharging of the liquid, a groove which is provided in the said neck concentrically to the weir and which the liquid passing over the weir enters, and a bar provided in the said groove and compelling the liquid to move in a direction opposite to the rotary direction of the bowl.

2. In means for reducing froth formation according to claim 1 the provision of a shield preventing the liquid leaving the separator from passing directly to the discharge open- 111g.

3. Means for reducing the froth formation according to claim 1 characterized by the groove having a throttled portion at the discharge opening.

In testimony whereof I have hereunto affixed my signature.

" eusrar WILHELM RUDA. 

